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82 Glossary The definitions of most of the following terms are taken directly from (1) the American Association of State Highway and Transportation Officials (AASHTO) October 2005 publica- tion A Policy on the Accommodation of Utilities within Freeway Right-of-Way (AASHTO 2005b); and (2) the AASHTO 2011 Roadside Design Guide, 4th Edition (AASHTO 2011b). Accident: A term used in older (early) highway safety literature to refer to either (1) a crash or collision between a motor vehicle and another vehicle, a person (i.e., a pedestrian or bicyclist), or a fixed object (e.g., a tree or utility pole); or (2) a vehicle that runs off of the road and rolls over. Arterial Highway: A general term denoting a highway primarily for through traffic, usually on a continual route. Average Annual Daily Traffic (AADT), also known as Average Daily Traffic (ADT): The number of motor vehicles that travel along a roadway on an average day throughout the year. The AADT value is often computed (estimated) based on applying an adjustment factor to a short-term traffic count. The adjustment factor is based on the particular day of the week, season of the year, and similar considerations. Barrier: A device that provides a physical limitation through which a vehicle would not normally pass. The barrier is intended to contain or redirect errant vehicles. Breakaway: A design feature that allows a device such as a sign, luminaire, or traffic signal support to yield or separate upon impact. The release mechanism can be a slip plane, plastic hinges, fracture elements, or a combination of these. Clear Zone: The total roadside border area, starting at the edge of the travel way, that is avail- able for safe use by errant vehicles. This area may consist of a shoulder, a recoverable slope, a nonrecoverable slope, and/or a clear run-out area. The desired width is dependent on the traffic volumes and speeds and on the roadside geometry. Clearance: The lateral distance from the edge of the traveled way to a roadside object or feature. Control of Access: The condition where the right of owners or occupants of abutting land (or other persons) to access, light, air, or view in connection with a highway is fully or partially controlled by public authority. Cost-Effective: An item or action taken that is economical in terms of the tangible benefits produced for the money spent. Expressway: A divided arterial highway for through traffic, with partial control of access and generally with grade separations at major intersections.
Glossary 83 Freeway: A controlled-access divided arterial highway with grade separations at intersections. Full Control of Access: Authority to control access that is exercised to give preference to through traffic by providing access connections with selected public roads only and by prohibiting crossings at grade or direct private driveway connections. High-Risk Utility Pole: A utility pole that is placed in a location in the roadway environment where there is an above-average risk of it being struck by an errantly controlled vehicle and where serious injury or death is a possible outcome of such a collision. Highway, Street, or Road: A general term denoting a public way for the transportation of people, materials, goods, and services but primarily for vehicular travel, including the entire area within the right-of-way. Longitudinal Barrier: A barrier whose primary function is to prevent penetration and to safely redirect an errant vehicle away from a roadside or median obstacle. Luminaire: A pole that carries overhead lighting and is usually made of metal. Some luminary devices are placed on utility poles, which are usually wood. Median: The portion of a divided highway separating the traveled ways for traffic that moves in opposite directions. Metal Utility Pole: A metal pole that carries utility lines, such as telephone, electric, or cable lines. These poles are rare because most utility lines are carried on wooden poles. Partial Control of Access: Authority to control access that is exercised to give preference to through traffic to a degree that, in addition to access connections with selected public roads, some crossings at grade and some private driveway connections may be allowed. Permit: The written agreement by which the transportation agency approves the use and occupancy of a highway right-of-way by utility facilities or private lines. A permit is also called an occupancy agreement. Private Lines: Privately owned facilities that convey or transmit the commodities outlined in the definition of utility facilities but are devoted exclusively to private use. Right-of-Way (ROW): A general term denoting land, property, or interest therein, usually in a strip acquired for, or devoted to, transportation purposes. Roadside: A general term denoting the area adjoining the outer edge of the roadway. Extensive areas between the roadways of a divided highway may also be termed roadsides. Roadside Crash Cushions: Reusable crash cushions with some major components that may be capable of surviving most impacts intact. Such components can be salvaged when the roadside crash cushion unit is being repaired. Roadway: The portion of a highway, including shoulders, for vehicular use. A divided highway has two or more roadways. Temporary Barrier: Temporary devices that are used to prevent vehicular access into construction or maintenance work zones and to redirect an impacting vehicle, thereby minimizing damage to the vehicle and injury to the occupants while providing worker protection. Traffic Barrier: A device used either (1) to prevent a vehicle from striking a more severe obstacle or feature located on the roadside or in the median or (2) to prevent crossover median crashes. As defined herein, there are four classes of traffic barriers, namely roadside median barriers, bridge barriers, railings, and crash cushions.
84 Utility Pole Safety and Hazard Evaluation Approaches Transportation Agency: The department, agency, commission, board, or official of any state (or political subdivision thereof) charged by its law with the responsibility for highway administration. Traveled Way: The portion of the roadway for the movement of through traffic. Utility Accommodation Policy: A statement of the policies and procedures used by a transpor- tation agency to regulate and accommodate utilities on the highway right-of-way. Utility Facility: A privately, publicly, or cooperatively owned line, facility, or system for producing, transmitting, or distributing communications, cable, heat, gas, oil, crude products, water, streams, waste, storm water not connected with highway drainage, or any other similar commodity, including any fire or police signal system or street lighting system that directly or indirectly serves the public. Utility Pole Crash: A traffic collision that involves a motor vehicle striking a utility pole. This term is consistent with other terms that safety researchers use to describe crash types. For example, pedestrian crashes, bicycle crashes, and mailbox crashes are defined as vehicles striking such people or objects. Yielding Utility Pole: An energy-dissipating pole that is designed to bend or break upon impact from a motor vehicle.